Marcus Aurelius — "Ask yourself: Is this necessary?"

"The faculty of reason is the only one which can contemplate itself, and by itself distinguish truth from falsehood, and the real from the unreal."

"You have power over your mind - not outside events. Realize this, and you will find strength."

"Consider how much more pain is brought on us by the anger and vexation caused by such acts than by the acts themselves, at which we are angry and vexed."

"The universal cause is a torrent. And how trivial are all things which are done in a state which is subject to change, and in what a sphere of things which are perishing!"

"Despise not death, but welcome it, for nature wills it like all else."